An IPD (Intelligent Power Device) is known as a semiconductor device used for an electronic component of equipment such as an automobile. The IPD has functions that monitor states of connected loads in the equipment. For example, one of the functions is called load open detection which checks whether or not a load is connected. If the load open occurs, the load is not connected appropriately. The function of the load open detection is required to execute the load open detection even when input is in an off-state (the IPD is in a non-operating state). Therefore, the IPD is provided with a dedicated input terminal separately from an input terminal for controlling an on/off of the IPD. Here, the dedicated input terminal is used for making a detection circuit and output circuit operate. The detection circuit executes the load open detection and the output circuit outputs an abnormality signal when abnormality is detected by the detection circuit. When the input is in an off-state (the IPD is in a non-operating state), a microcomputer intermittently (periodically) inputs a control signal into the dedicated input terminal and thereby the IPD intermittently (periodically) checks the state of the load.
As a related art, a motor control device is disclosed in JP 2007-53894 A (related to US2007035896 (A1)). The motor control device includes a motor operating by being supplied with electric power from a vehicle power source and a control section controlling the motor driving. The control section includes an estimation temperature calculating means, a mode switching means and an activating means. The estimation temperature calculating means calculates an estimation temperature of the motor. The mode switching means switches an operation mode of the control section from a normal operation mode enabling the motor driving to a sleep mode consuming less electric power than that of the normal operation mode based on a predetermined condition when the motor is stopped. The activating means makes the estimation temperature calculating means operate during a predetermined active time period every predetermined sleep time period in the sleep mode. The estimation temperature calculating means calculates the estimation temperature during the active time period.